1610s, "action of delegating" (earlier in this sense was delegacie, mid-15c.); perhaps a native formation, perhaps from French délégation, or directly from Latin delegationem (nominative delegatio) "assignment, delegation," noun of action from past participle stem of delegare (see delegate). Meaning "persons sent by commission" is from 1818; meaning "a state's elected representatives, taken collectively," is U.S. political usage from 1820s.